98 BULLETIN 116, UNITED STATES NATIONAL. MUSEUM. 



differs in having the fourth joint of middle tarsi compressed and 

 widened, in the middle and hind f(>mora eaeh having two preapieal 

 hj-istlcs, and in having the posterior tihiae narrowly black at tip. 

 The next speciies, culultus is even more closely related to renius than 

 is incon(jruus, as it has the same narrow black tip to hind tibiae, 

 tliey differ only in the plain middle tarsi of adaltus, and in its having 

 only one preapieal bristle, it differs from incoiKjrvMS in the narrow 

 black tip of the liind tibiae. 



No. 55. DOLICHOPUS ADULTUS, new species. 



Male. — Length 5 mm.; of wing 4.5 mm. Face rather wide, 

 narrowed a little below, silvery white, a little grayish. Front blue 

 green, sometimes with violet reflections at vertex. Antennae (fig. 

 55&) wholly black; third joint large, three times as long as wide, 

 pointed at tip; arista about as long as the antennae, inserted at 

 apical third of upper edge. Orbital cilia wholly black. 



Thorax dark green with coppery reflections; dorsum very shining; 

 pleurae dulled with gray pollen. Abdomen a lighter green with 

 black incisures, dulled with white pollen, which forms large spots on 

 the sides of the segments. Hypopygium black with coppery reflec- 

 tions on basal part; its lamellae (fig. 55a) small, dark brownish to 

 whitish with the edges and tip black, fringed with black hairs, some- 

 what triangular in outline with a rather sharp point at outer corner. 



Coxae black with the tips narrowly yellow; anterior pair with 

 white pollen and little black hairs on the front surface. Fore and 

 hind femora black with the tips of the former broadly, of the latter 

 narrowly, yellow. Middle femora black at base, becoming yellow at 

 about basal third on upper and lower edges, the yellow extending 

 nearer the base on the sides. Middle and hind femora each with one 

 preapieal bristle, the latter not ciliated below. Tibiae yellow; 

 posterior pair black at tip for less than one-fifth their length; a slight 

 swelling just before their middle can be seen when viewed from above, 

 and the tips are a little thickened; the glabrous stripe on upper edge 

 is wide, reaching narrowly inside of the inner row of bristles. Lower 

 surface of middle tibiae with one bristle near apical third and one near 

 basal third. Fore and middle tarsi black from the tip of the first 

 joint, the former about as long as their tibiae, fourth and fifth joints 

 of nearly equal length, third a little longer, the middle tarsi one and a 

 fourth times as long as their tibiae. Hind tarsi wholly black, (^alyp- 

 ters pale yellow with black cilia. Hal teres yellow, their stems darker. 



Wings (fig. 55) grayish, slightly tinged with brown in front of 

 second vein; root of wing yellow; costa very slightly enlarged at tip of 

 first vein; last section of fourth vein bent at basal third, beyond 

 which it is very nearly parallel with third vein; hind margin of wing 



